Integrated 1D-2D Modeling

Overland flood flows are potentially problematic for a strictly 1D solution: there may be multiple flow pathways around and through obstructions, and overland flow paths can be ill-defined and variable between flood events. PCSWMM can provide accurate 2D modeling of flood depths, flows and velocities for both urban and rural applications, including river-based flooding, major/minor (dual drainage) modeling, or simply overland routing of rainfall runoff. Sources of 2D surface flows can be overbank flooding from rivers/streams, flooding from minor system, and/or distributed rainfall.

PCSWMM provides a completely integrated approach to 2D modeling, allowing the modeller to seamlessly transition back and forth between 1D and 2D modeling. This allows for dynamic major/minor system modeling, modeling of multiple culverts and/or bridges within the 2D flood plain, incremental dam failure, and full-scale 1D-2D watershed modeling, where only specific sections of the drainage system are modeled in 2D. Additional advantages include full 2D support for water quality modeling, snowmelt, control rules (real-time control simulation for pumps, gates, dams, etc.), storage devices, and distributed hydrology.

On the model building side, tools are provided for:

• automatic unstructured or structured mesh generation,
• adaptive/variable mesh resolution,
• directional, bendable mesh creation for channel flow,
• edge definition for abrupt elevation changes (i.e. low walls, retaining walls, curbs, etc.),
• computing average cell elevation from DEMs (sampling across cell), and
• non-point boundary conditions (i.e. defining boundary conditions across borders of the 2D model)

For post-run analysis, PCSWMM provides:

• thematic rendering of 2D layer,
• fast animation of 2D simulation results, complete with velocity vectors,
• HD video recording of animations, with standard or custom dimensions and compression settings,
• depth and velocity time series for all 2D cells,
• flow time series across user-defined threshold lines,
• custom risk maps defining various risk zones based on multiple user-defined criteria,
• maximum or instantaneous depth and/or velocity contour generation,
• Google Earth/Map overlays, including 3D thermometer style plots, and
• GIS/CAD output of flood extents, risk maps, contours, etc. in many supported formats, including SHP, TAB, MIF, DXF, GML, and many more.